1. Field of the Invention
The present invention relates to a backlight assembly, and more particularly, to a combinative edge lighting backlight assembly with misaligning light sources and light guide plates.
2. Description of the Prior Art
In a traditional edge lighting backlight assembly, light enters from the side. Such structure makes it difficult to maintain light uniformity as the size of the backlight assembly increases. Combination of a number of smaller-sized light guide plates to form a large light guide plate is therefore carried out, each smaller-sized light guide plate receiving light from a stand-along light module, such that a large size edge lighting backlight assembly can still have its luminance and uniformity above a standard.
Compared to the single large-sized light guide plate, light emitted from every block of the combination of all the small-sized light guide plates may differ from one another, because of the difference of physical property of each light guide plate and the light module, and the way the light guide plates assemble with the light modules. On the other hand, the joint between two light guide plates shows discontinuity. The edge fault of the light guide plate is a common problem in the combinative backlight assembly because the backlight assembly is configured with a light source corresponding to a light guide plate.
Additionally, when a direct-type backlight assembly uses light emitting diodes (LEDs) as the light source, turning on part of the LEDs can save power for the backlight assembly, when maximum Luminance is unnecessary. The backlight assembly can also have greater contrast by turning on only part of the LEDs. Such technique is called local dimming. Please refer to FIG. 1. FIG. 1 is a diagram of display effect of a display 10 when a combinative edge lighting backlight assembly performs its local dimming function according to the prior art. When applying local dimming function on an edge lighting backlight assembly, however, the edge between a block with light turning on and a block with light turning off can be much more obvious since the light guide plate and the light source are configured one by one Although the direct-type backlight assembly has better performance with local dimming, the thickness of the direct-type backlight assembly is greater than that of the edge lighting backlight assembly.